Running Lights Not Working on Trailer With New Wiring

Question:

I just installed new wiring from front to back on trailer. I have great bright brake and turn lights but no running lights. I have tried both plugs on 2017 ram and checked all fuses. I need help

asked by: Joe

Expert Reply:

Start off by making sure you connected the tail/running lights to the appropriate pin on your trailer's 4-Way or 7-Way depending on what kind of connector you have.

For a 4-Way the pin should be the brown colored wire. This will also be the pin that is closest to the female ground connection part. For a 7-Way it will be the pin that is in the 1 o'clock position. Also check the connectors both on your tow vehicle and trailer to make sure there is no corrosion or debris.

Once you have confirmed that this is correct and they are clean you will then want to make sure that your grounds are all clean. You want metal to metal contact both on your tow vehicle and trailer end.

Also make sure to check that all of your wiring connections are still good. Especially at the tail/running lights.

Moving on from there the next step would be to make sure that your Ram is actually sending a signal for the tail/running lights. You can use a Circuit Tester # PTW2992 to test the pin locations (they will be the opposite of what I said will be on the trailer's side).

If your Ram is sending a signal and the wiring on your trailer looks good then you will need to take your trailer to your local shop so that they can physically inspect it.

expert reply by: Jon G